As the demand for smaller electronic products grows, manufacturers and others in the electronics industry continually seek ways to reduce the size of integrated circuits used in electronic products. In that regard, three-dimensional type integrated circuit packaging techniques have been developed and used.
One packaging technique that has been developed is Package-on-Package (PoP). As the name implies, PoP is a semiconductor packaging innovation that involves stacking one package on top of another package. A PoP device may combine vertically discrete memory and logic ball grid array (BGA) packages. In PoP package designs, the top package may be interconnected to the bottom package through peripheral solder balls.
Applications for such multiple chip packages are numerous. Because certain types of dedicated devices are commonly used, it is often needed to put these devices together to complete a functional design for a particular use. Combining microprocessor devices with program memory storage such as FLASH or EEPROM devices, combining microprocessors with application specific processors, such as baseband transceivers, graphics processors, cache memory devices, memory management devices, and analog to digital converters, are all useful and commonly used arrangements that provide applications for the structures described herein.
Such multiple chip packages often exhibit thermal coupling between packages. The performance of many devices is sensitive to temperature and can become degraded as temperature increases. Additionally, many processing units, such as accelerated processing units (APUs), are heat generators. Thus the application of multiple chip packages requires added consideration of the thermal management with regards to the thermal coupling between chip components and between chip packages.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale.